Theoretical investigation of the photocatalytic mechanism of single Au adsorption on the Bi4O5Br2 (−1 0 1) surface

Abstract First-principle calculation based on DFT is performed to explore the structural, electronic, optical properties and photocatalytic mechanism of monatomic Au/Bi4O5Br2 adsorption systems. The results indicate that Au/Bi4O5Br2 adsorption systems not only possess excellent structural stability and appropriate band structure, but also exhibit excellent photon-excited carriers generation efficiency. The optical absorption is strengthened and performs significant phenomenon of redshift. The modification method through monatomic Au absorption causes the charge redistribution of the Bi4O5Br2 (−1 0 1) surface, achieving the effective spatial separation of the oxidation center and the reduction center. This significantly improve separation efficiency of the photo-excited electrons and holes. These characters make the Au/ Bi4O5Br2 adsorption system an excellent photocatalyst.